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헬름홀츠 공진에서 톱니 효과에 대한 수치적 연구

이승수;전민우;이수갑
Lee, Seungsoo;Jeon, Minu;Lee, Soogab

  • 투고 : 2015.07.09
  • 심사 : 2015.11.17
  • 발행 : 2016.01.20

초록

The flow-excited Helmholtz resonance phenomenon was investigated numerically using Reynolds averaged Navier-Stokes approach. The fundamental cause of the Helmholtz resonance phenomenon is known as shedding of a single discrete vortex from orifice edge that travels during one period of the oscillation. In this study, serrated deflector, which is biomimetic design of the owl's feather, is used to split a single vortex into small vortices. Rectangular deflector and serrated deflector are compared with numerical results of pressure and streamline inside the cavity. Consequently, the serration breaks the shedding period of vortex core and eliminates the resonance. Also, it changes the flow pattern in according to the location of different serration height. By making inflows and outflows occur simultaneously in spanwise direction in the cavity, the period of Helmholtz resonance disappears. Comparing between rectangular deflector and serrated deflector, the serrated deflector can deal with the Helmholtz resonance more effectively.

키워드

헬름홀츠 공진;톱니 디플렉터;톱니 효과

참고문헌

  1. Nelson, P. A., Halliwell, N. A. and Doak, P. E., 1981, Fluid Dynamics of a Flow Excited Resonance, Part Ⅰ: Experiment, Journal of Sound and Vibration, Vol. 78, No. 1, pp. 15~38. https://doi.org/10.1016/S0022-460X(81)80156-3
  2. Harrington, M. C., 1957, Excitation of Cavity Resonance by Air Flow, Presented at the Meeting of the Division of Fluid Dynamics of the American Physical Society, New York.
  3. Balasubramanian, G., Crouse, B. and Freed, D., 2009, Numerical Simulation of Leakage Effects on Sunroof Buffeting of an Idealized Generic Vehicle., AIAA 2009-3348
  4. Ver, I. L., 1987, Noise of Jet Engine Test Cells, Naval Facilities Engineering Command, Jet Engine Test Cell Meeting.
  5. Hersh, A. S. and Hayden, R. E., 1971, Aerodynamic Sound Radiation from Lifting Surfaces with an Without Leading-edge Serrations, NASA Technical Report CR-114370.
  6. Howe, M. S., 1991, Aerodynamic Noise of a Serrated Trailing Edge, Journal of Fluids and Structures, Vol. 5, No. 1, pp. 33~45. https://doi.org/10.1016/0889-9746(91)80010-B
  7. Howe, M. S., 1991, Noise Produced by a Sawtooth Trailing Edge, Journal of the Acoustic Society of America, Vol. 90, No. 1, pp. 482~487. https://doi.org/10.1121/1.401273
  8. Kim, T. H., 2014, A Numerical Study on Generation and Reduction of Rotating Blades Broadband Noise, Ph.D. Thesis, Seoul National University.
  9. Iaccarino, G., Ooi, A., Durbin, P. A. and Behnia, M., 2003, Reynolds Averaged Simulation of Unsteady Separated Flow, International Journal of Heat and Fluid Flow, Vol. 24, No. 2, pp. 147~156. https://doi.org/10.1016/S0142-727X(02)00210-2
  10. Wang, Y. P., Lee, H. C., Li, K. M., Gu, Z. Q. and Chen, J., 2012, Experimental and Numerical Study of Flow Over a Cavity for Reduction of Buffeting Noise, Acta Acustica United with Acustica, Vol. 98, No. 4, pp. 600~610. https://doi.org/10.3813/AAA.918541
  11. Ashcroft, G. B., Takeda, K. and Zhang, X., 2003, A Numerical Investigation of the Noise Radiated by a Turbulent Flow Over a Cavity, Journal of Sound and Vibration, Vol. 265, No. 1, pp. 43~60. https://doi.org/10.1016/S0022-460X(02)01439-6

과제정보

연구 과제번호 : 융합지식기반 창조형 기계항공인재 양성사업단

연구 과제 주관 기관 : 서울대학교